Access a folder on generic user's Windows Desktop using C#

Hello Experts,

I am accessing a folder on the user's Windows Desktop like this:
string strObsFile1 = @"C:\Documents and Settings\Tom\Desktop\My Folder\MyFile.exe

This works fine for the user "Tom" but I would like the string to be  generic way so the it does not matter which user is logged on...

I tried this but it did not work:
string strObsFile1 = @"C:\Documents and Settings\%User%\Desktop\My Folder\MyFile.exe

Does anyone know how to do this?

Thanks!